Which of the following drugs was most likely prescribed for the patient with past episodes of depression and mania?

Correct Answer: C

Rationale: The correct answer is C: Lamotrigine. This drug is commonly prescribed for patients with past episodes of depression and mania as it is a mood stabilizer effective in treating bipolar disorder. It helps in regulating mood swings and preventing both manic and depressive episodes. Valproic acid (A) is also a mood stabilizer, but Lamotrigine is more commonly used in this context. Aripiprazole (B) is an atypical antipsychotic often used for bipolar disorder but is not as specific for treating past episodes of depression and mania. Imipramine (D) is a tricyclic antidepressant used for major depressive disorder and not typically prescribed for bipolar disorder.

Correct Answer: B

Rationale: The correct answer is B: Dextroamphetamine. This drug is a stimulant commonly prescribed for attention deficit hyperactivity disorder (ADHD) in children. It helps improve focus and control impulsivity, addressing symptoms like inability to sit still in school. Cocaine (A) is a highly addictive illegal drug with no therapeutic use in this context. Methylphenidate (C) is another stimulant used for ADHD. Guanfacine (D) is a non-stimulant medication that is typically used as an alternative treatment for ADHD-related symptoms, but it is less likely to be prescribed for a child unable to sit still in school compared to stimulant medications like Dextroamphetamine.

Correct Answer: D

Rationale: The correct answer is D: Buprenorphine. Buprenorphine is commonly used to treat opioid addiction and dependence due to its partial agonist activity at the mu-opioid receptor, which helps reduce cravings and withdrawal symptoms. Methadone (A) is also used for opioid addiction treatment but is more commonly administered in specialized clinics. Meperidine (B) is primarily used for acute pain management and has a high potential for toxic metabolites. Codeine (C) is a weaker opioid commonly used for mild to moderate pain and cough suppression, not typically used for addiction treatment.

Correct Answer: D

Rationale: The correct answer is D because methadone stimulates adenylyl cyclase activity as a postreceptor mechanism. Methadone is an opioid receptor agonist that activates G-protein coupled receptors, leading to the activation of adenylyl cyclase and subsequent increase in cAMP levels. This increased cAMP signaling pathway results in various downstream effects, including modulation of neurotransmitter release and neuronal excitability. A: Inhibition of the synthesis of inositol triphosphate/diacylglycerol (IP3/DAG) is not a postreceptor mechanism triggered by methadone. B: Blockade of Ca2+ channels on presynaptic nerve terminals is not a postreceptor mechanism triggered by methadone. C: Opening of Na+ channels on neuronal cell membrane is not a postreceptor mechanism triggered by methadone. In summary, methadone's stimulation of adenylyl cyclase activity is the correct choice as it align

Correct Answer: B

Rationale: The correct answer is B: Morphine. Postoperative adynamic ileus is characterized by delayed gastric emptying and reduced intestinal motility. Morphine can exacerbate these symptoms by causing further gastrointestinal motility issues, leading to potential complications such as bowel obstruction. Acetaminophen (A), Ibuprofen (C), and Ketorolac (D) do not have significant effects on gastrointestinal motility and are therefore safer choices for patients with postoperative adynamic ileus.